<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <h2>JS原生绑定事件--dom0级事件绑定</h2>
    <button class="btn">绑定事件</button>
</body>
<script>
    //获取dom
    const btn = document.querySelector('.btn')

    //给btn绑定事件
    btn.onclick = aa;
    btn.onclick = bb;

    function aa() {
        console.log('我是aa函数')
    }

    function bb() {
        console.log('我是bb函数')
    }
</script>

</html>